The discussion about the benefit of nuclear power for the global climate is kinda broken on both sides. Supporters keep claiming that nuclear power is “free of CO2”. The other side brings up claims like “nuclear power has a higher CO2 output than coal powered plants”. Both arguments are nonsense.
Emissions before and after power generation
You can’t just count the CO2 produced during the actual power generation. To generate nuclear power, the nuclear fuel (uranium) has to be mined and purified. Then, it has to be pressed into fuel rods and transported to the power plant. When it reaches the end of its lifetime, it has to be stored somewhere (indefinitely). There is also a lot of machinery involved which needs to be built and maintained. All this consumes energy and releases CO2 into the atmosphere – directly or indirectly.
Unfortunately, it is hard to find some solid assumption about the overall CO2 output of nuclear power plants. They range from 8 to 65 grams per kilowatt hour produced electricity. The storage of the nuclear waste isn’t even included in these assumptions.
For comparison: According to the same sources, fossile energy production release at best 370g/kWh (natural gas CCPP).
A new study by Jan Willem Storm van Leeuwen and Philip Smith says that nuclear power produces 90 to 140 grams CO2 per kilowatt hour. I took these numbers from secondary sources, though, since I couldn’t locate a clear statement about that in the original study.
Long term perspectives
CO2 emissions of nuclear energy depend primarily on the fuel production. The future production of uranium is controversially disputed.
The “Deutsche Physikalische Gesellschaft” (DPG) sees no problems in future nuclear fuel production. According to them, only a small part of the global uranium deposits have been discovered yet.
An intensive prospection happened only between 1970 and 1985. The yearly effort was minimal compared to the investments into the search for other energy sources like oil.
(translated from Klimaschutz und Energieversorgung in Deutschland 1990 – 2020, S. 68)
Critical voices see that a little less optimistic. They predict a declining uranium concentration, which increases the CO2 output during enrichment. In the worst case the energy required to enrich the uranium could even exceed the amount of energy that can be retrieved in the nuclear power plants.
This article is not meant as a statement for or against nuclear energy. It is only meant to bring some facts into the discussion about nuclear energy in context of the climate crisis. Additional facts are very much welcome, because they are hard to find.
Also don’t forget that despite the current discussion about change of climate, there are other factors that need to be put into consideration when discussing nuclear energy. There is not just CO2 emissions, but also security, nuclear waste which has to be stored over countless generations, etc…
Serik.de: Schont Atomenergie das Klima?
Dr. Ludwig Lindner: CO2-Bilanz von Stromerzeugunsanlagen im Lebenszyklus
Deutsche Physikalische Gesellschaft (DPG): Klimaschutz und Energieversorgung in Deutschland 1990 – 2020
Ulf Bossel: Das Märchen vom CO2-freien Atomstrom
ISA, The University of Sydney: Life-Cycle Energy Balance and Greenhouse Gas Emissions of Nuclear Energy in Australia
Nuclear power the energy balance by Jan Willem Storm van Leeuwen and Philip Smith